Surgeons have come to use staples for closing wounds or incisions in the skin and fascia instead of conventional thread sutures in surgical operations. One of the main reasons for this trend is that the conventional suture which involves insertion of a thread means by a curved needle and then tying the ends of the thread is quite time-consuming. There are various operations in which a large number of sutures must be used. Thus, for example, in heart surgery where coronary by-pass procedures are performed, the by-passes are usually made from the saphenous vein in the leg. It is common to perform as many as six incisions in the leg from the ankle to the groin in dissecting out the saphenous vein from which the by-passes are to be made. The several incisions involved may vary from perhaps two inches in length to six or seven inches in length. With conventional thread sutures the closing of such wounds would take perhaps an hour to an hour and a half, whereas with surgical staples as many as fifty staples may be emplaced in a matter of ten to twenty minutes. This saving of time is of great importance in that it not only saves the surgeon's time but it reduces fatigue on the part of the surgeon and it substantially reduces the length of time the patient must be maintained under anesthesia. It is generally recognized that the shorter the time the patient is under anesthesia, the more rapid is his recovery and the less trauma is involved.
Some presently available surgical staples are generally shaped like conventional staples that are used in wood or paper except that they are generally wider and have short legs. They are formed about an anvil into a box configuration. There has been observed a tendency for the points of such staples to slide across the skin along their cut surfaces before penetrating and in doing so the staples may tend to separate the wound before the points actually penetrate the skin. In the conventional staple, the points are relatively close to the forming corners of the anvil about which they are formed when the staple first contacts the skin and again when the staple contacts the anvil. Thus, they do not always obtain a secure and effective wound closing since in order to accomplish this the staple must gather skin and tissue sufficiently to close the wound and to cause the edges of the wound to be brought into approximation.
The staple according to Rothfuss, U.S. Pat. No. 4,014,492 prior to emplacement is configured with a central portion, a straight portion extending upwardly and outwardly from each end of the central portion at an obtuse angle, and a relatively short straight portion extending downwardly and outwardly from each of said upwardly and outwardly extending portions. The downwardly and outwardly extending portions have vertical cuts to produce sharp points at the ends of the downwardly and outwardly extending portions. The vertical cuts will be normal to the surface of the skin at the time of initial contact. The disposition of the points with respect to the forming anvil produces an eversion of the wound which insures proper approximation and better and more rapid healing.
In Becht, et al., U.S. Pat. No. 4,261,244, there is provided in a surgical staple for use in suturing the skin or fascia of a patient and of the type having an elongated, substantially horizontal crown portion terminating in downwardly depending leg portions having points formed at their free ends, the surgical staple, together with a plurality of identical surgical staples, being adapted to straddle and to be fed along guide means to the anvil of a surgical stapling instrument which bends end portions of the surgical staple crown downwardly so that the leg portions are substantially coaxial with their points approaching each other.
The improvement in Becht '244 comprises a first pair of diametrically opposed front and rear flats and a second pair of diametrically opposed top and bottom flats on the surgical staple. The front and rear flats of the first pair extend respectively along the front and rear of the crown and leg portions of the surgical staple. The diametrically opposed flats of the second pair are disposed at 90.degree. to the first pair of flats. The top flat of the second pair extends along the upper surface of the surgical staple crown portion and the outsides of its leg portions and the bottom flat of the second pair extends along the underside of the surgical staple crown portion and along the insides of its leg portions. The front and rear flats of the first pair, cooperate with similar flats on adjacent surgical staples, to assure proper feeding of the surgical staple along the surgical instrument guide means. The top and bottom flats of the second pair, cooperate respectively with the surgical stapling instrument former and anvil, to prevent undesirable axial rotation of the surgical staple crown portion during the forming and implanting thereof in the skin or fascia of a patient.
Staples of the referenced art and of the present invention are provided in a cartridge, and the configuration of the staple disclosed herein substantially improves the space factor and makes it possible to stack more staples in a given space in a cartridge than is possible with staples of conventional form.
Yet, certain deficiencies have been noted in current surgical staples. If the user wishes to staple mesh around, for instance, a blood vessel, or there is an organ needed to hold closed by mesh, it is difficult to staple current shaped staples into this mesh. That is, the staples hold the mesh materials loosely, and in some instances too loosely. It would be more desirable to have a staple which holds mesh more snugly, and yet remains easy to form. Also, of course, it would be desirable that this staple is capable of emplacement, either in tissue or in mesh, without rotation. The staples of this sort are more conducive, to withstand rotation also, if they are not "box" shaped. At times, the box shaped staples are difficult to form so that the entire box is closed, and appropriate tissue eversion is derived. Therefore, at times it may be more preferential to form a surgical staple in a non-box shaped configuration.